Planetary Radio: Space Exploration, Astronomy and Science - Genesis Returns With a Bit of the Sun

Episode Date: August 30, 2004

Genesis Returns With a Bit of the SunLearn more about your ad choices. Visit megaphone.fm/adchoicesSee omnystudio.com/listener for privacy information.See omnystudio.com/listener for privacy information.

Genesis comes home with a piece of the Sun on Planetary Radio. Hello again everyone and welcome back to the travel show that takes you to the stars. One star in particular this week, our own Sun, as the first sample return mission in decades arrives back at Earth. Our guest is Don Burnett, the principal investigator and lead scientist for the Genesis mission, which will be dropping down into the Utah desert on September 8. First, let's take a quick look at some of the other stories coming to us from around the galaxy. There's big news in the search for extrasolar planets, or ESPs.

Astronomers have already found well over a hundred planets circling other stars, but their holy grail is to locate another Earth. A European team has just found one that's only a few times as big as our home, and there was at least one other announcement planned as we put together today's show. Cassini-Huygens is in great shape as it orbits Saturn, according to its Jet Propulsion Lab controllers. The huge spacecraft successfully fired its main engine for the last time, placing it on precisely the path needed to complete its mission. And more than five million SETI at Home team members

can now listen for things that go boink in the night. Boink stands for Berkeley Online Infrastructure for Network Computing. It's the brand new software for the world's largest distributed computing project and is expected to make it much easier for research to move beyond the search for extraterrestrial intelligence and into many other fields that could benefit from the massive computational power of PCs all over the globe. For the details of these and many other stories, visit us on the web at planetary.org.

I'll be right back after this timely visit with Emily. timely visit with Emily. Hi, I'm Emily Lakdawalla with questions and answers. A listener asked, When they report times for events happening on the Mars Exploration Rover mission, what do those times mean? Are they the time for the rovers, Mars times, or the times that signals are received on the Earth?

There are many different ways of reporting event times on missions. For the most part, events on planetary missions, including the Mars Exploration Rovers, are reported using Universal Time Coordinates, or UTC. UTC is the worldwide scientific standard of timekeeping. It is based upon atomic clocks and is accurate to within microseconds. But what happens to the time of spacecraft events when they get so far from Earth that this spacecraft's signals take seconds, minutes, or even hours to get here? Stay tuned to Planetary Radio to find out. Don Burnett is principal investigator and lead scientist for the Genesis mission.

When I visited him recently on the Caltech campus in Pasadena, he was busily preparing for a trip to the Utah desert where, on September 8, a bit of the sun will literally come down to Earth. Don Burnett, first of all, thank you for inviting us into your office on what must be, I assume, is a pretty busy time with what you've got in store in the next few days. Yes. Well, we do appreciate it. probably written 40, 50 years ago, about a group of scientists in a rocket who dipped down to the surface, so-called, of the sun

to scoop up part of the sun's material and take it back to Earth and analyze it. It doesn't end very well. You and your team have found a much more practical way of doing this. I'd actually like to have a reference to that story. I was unaware of it. I'll look of it. Yeah, I think what we're doing is a lot easier than Mr. Bradbury thought about. Give us a capsule description of what Genesis is all about. What we have done is we've taken ultra-pure materials. We've taken them outside of the range of the Earth's magnetic field.

We've exposed them to the solar wind, which is individual ions flowing out from the surface of the sun. These ions have hit and stuck and embedded themselves in our material. We closed up all our canister, which has all these materials, and we are almost back to Earth as we speak. I was looking at the website last night, also in preparation for this, and I saw a diagram of the trajectory of your mission, which has been in space now for how many years?

We launched in almost exactly three years ago, August the 8th, 2001. Your spacecraft had one of the oddest looking trajectories I've ever seen a picture of, and I guess for good reason, because of where it had to go. Well, the L1 point is a great point that's easy to get to for any spacecraft that's observing the sun. In fact, it's almost a parking lot for a solar observing spacecraft. Now, what we do is a little bit different. We come back. That's a little different. And L1, for any of our audience that don't know, the Lagrange point, of which there are several, and this one happens to be between the Earth and the Sun.

On the line between the Earth and the Sun. And so you were actually orbiting that space, that spot. That's right. I didn't stop to think that you've had other company out there, other solar observing spacecraft. Now we are almost at the point where on the 8th, the 8th of September, talk about what's going to happen on that day. Okay. In the last couple of days before the mission, we are pointed to a point in northeast Nevada. in northeast Nevada.

And then as we begin to come closer to the time of reentry, we check everything on the spacecraft. We check where it's heading, that everything is working. And then we send up a command that says, come on in and release our sample return capsule. And then that happens about 6 in the morning in Utah time on the 8th of September, and four hours later, it's on its parachute descending back to the Earth. And some of our audience has probably heard about how you're going to capture that spacecraft

with a little help from Hollywood. A bit of a clarification there. There's been a lot of press about Hollywood stunt pilots. We got these pilots because they're the best ones you could find. They just happen to be employed. Their other customers are Hollywood. They just said, that's a coincidence. We got these pilots because they're the best ones you could find. They just happen to be employed. Their other customers are Hollywood. That's a coincidence. We got them because they're good, and they are quite good.

All right, we don't want the capsule on its parachute to hit the ground. We have fairly fragile collector materials in there that now have some cracks in them from micrometeorites. We don't want them rallying around and getting their surfaces scratched, in which case we would lose our signal. Therefore, we have planned from the very beginning to use the helicopters in the mid-air recovery to keep the capsule from parachuting to the ground. And so this helicopter, and I guess there is a backup helicopter as well,

are going to attempt to snag the spacecraft or its parafoil when it's still, what, about 10,000 feet up? That's right. It's a little faster. If they're standing beside it, they may let it go to seven or eight. But they have the capability of catching it at nine to ten if they had to. How can you be so confident? I mean, have our abilities to target a landing spot improved so much since, let's say, the Apollo days?

That helicopter, you're pretty confident you're going to be where you need to be. The navigation people have learned how to drive this spacecraft. They've been doing it with excellent performance for three years. They calculate how it's going, how fast it's going, the direction it's going. They can predict where it's going to land quite accurately. So we have a delivery ellipse, which I think is 30 kilometers by 45 kilometers, something like that. And they have 99% confidence that they will put the spacecraft in that ellipse. Well, I suppose if we can hit similar ellipses on Mars, we should be able to do it on our home planet. I don't know the size on Mars. It may or may not be similar,

but yes, it's the same idea. That is certainly more difficult, what we're doing here. The spacecraft, which is coming back, you know that it contains the samples. What kind of data have you been collecting from this spacecraft, even prior to its return to Earth? We have solar wind monitors on the spacecraft that were built by Los Alamos that monitor the positive ions and the electrons in the solar wind. And so we have a pretty good record of what the solar wind has done over the last two years. We have been studying the sun for many years. It's been spewing out these particles, solar wind, in every direction for its entire lifetime, much longer than ours. We have spectrometers.

Why do we know so little about the sun? First of all, this is a little different. It is very different, as a matter of fact, from previous spacecraft that studied the solar wind because they've been studying the solar wind for the sake of learning about the solar wind. The solar wind for us is a means to an end. It's a sample of solar matter. This is a planetary science mission. We want to know, to a fairly high degree of precision,

the relative amounts of the different elements, and what's most important for us, the relative proportions of the different isotopes of the elements. In terms of the relative amounts of elements, indeed, one can analyze the absorption spectrum of the sun, and there's data on the composition for most, although not all, but most of the elements.

The genesis goals here are to prove the accuracy of those abundances by a factor of three. Moreover, there is very little known about the isotopic composition, and certainly not for the degree of accuracy you need for planetary science purposes. And that's our main science objective is to do these isotopic compositions. Because with a spectrometer, you may be able to see what elements are there, but you can't tell whether it's an isotope. It's not impossible. It's very difficult. It's very difficult to do precisely.

Of course, this is the first sample return mission in a long, long time. Now, it would be natural for me to ask you what was the last sample return, but don't say that because that's going to be our trivia contest at the end of today's show. I know within a couple years or so, I know the answer. I could win that one. Well, you're not allowed to answer. Clearly, this is something that happens rarely and is one of the factors. Let me correct you a little bit. It has happened rarely.

Looking to the future, this will not be a rare event. We now have the technical capability of doing a serious exploration of the inner solar system with sample return missions. And already on the books, we have Stardust bringing back grains from the coma of a comet. in the books, you have Stardust bringing back grains from the coma of a comet. And very early in 2006, you have a Japanese mission that's launched on its way to bring back a sample of an Earth-crossing asteroid. There are proposals that are very viable proposals to sample the moons of Mars and also to do more extensive asteroid sampling. There is a major effort to sample material from the Aitken Basin on

the south pole of the moon, which is a very deep, old basin of excavated materials from deep inside the lunar interior. And so it goes on and on. I mean, this is the first of a new wave in the 21st century of sample return missions. So not too much to look back to, at least over the last couple of decades, but much more to look forward to. That's right. You mentioned Stardust.

I want to come back to that, this other mission, which will sometime in the years. Our sister mission, yes. And I was wondering about exactly that. But if we should talk about that maybe when we come back from a quick break. Our guest today is Donald Burnett, Caltech professor, planetary scientist, principal investigator, and lead scientist for the Genesis mission, which, as we speak, is about to return a little bit of the sun to good old planet Earth. We'll be right back.

This is Buzz Aldrin. When I walked on the moon, I knew it was just the beginning of humankind's great adventure in the solar system. That's why I'm a member of the Planetary Society, the world's largest space interest group. The Planetary Society is helping to explore Mars. We're tracking near-Earth asteroids and comets. We sponsor the search for life on other worlds, and we're building the first-ever solar sail. You can learn about these adventures and exciting new discoveries from space exploration in The Planetary Report. The Planetary Report is the Society's full-color magazine.

It's just one of many member benefits. You can learn more by calling 1-877-PLANETS. That's toll-free, 1-877-752-6387. And you can catch up on space exploration news and developments at our exciting and informative website, PlanetarySociety.org. The Planetary Society, exploring new worlds. Welcome back to Planetary Radio where our special guest is Don Burnett. He is the principal investigator and lead scientist for the Genesis mission, now in the very last few miles or kilometers of its trip back from the L1 Lagrange point where it has been collecting nothing less than bits of the sun.

He is a Caltech professor, planetary scientist, and we are speaking in his office. And when we got here, you were making your hotel reservation for Utah. Let's talk about that other mission that you mentioned, Stardust, which you called your sister mission, which I wondered if that might be the case. The similarities are we are a sample return mission. A lot of the technology and reentry and things like that we have in common. Their reentry capsule is a lot smaller than ours, but the main complementarities in terms of the science, it's sort of an inside-outside approach to understanding the composition and origin of the solar system. We are bringing back the inside samples of materials preserved in the surface of the layers of the sun, which represents the composition of the solar nebula from which

all planetary materials form. Stardust, in fact, is bringing out materials that form in the far reaches of the solar system. So we are looking at different aspects of the solar system from deep inside and from far outside. Fascinating contrast. And, of course, they won't be returning their samples for a little while yet. January 2006, I believe. Yeah, not too far off. The samples that are being returned by Genesis,

what happens with those after the helicopter snags that sample return capsule? Okay, inside the capsule, there is another can, which contains all the materials, which is locked up and sealed back at L1. When we get the reentry capsule back on the ground, we will open the first lid of it, and we will put on a nitrogen purge into a canister which has all our collector materials that will sweep out all the gases and the combustion products we might have incorporated inside the canister in the upper atmosphere.

And then the canister itself and all the different pieces of the capsule will be boxed up and shipped to the Johnson Space Center. And there, in a state-of-the-art Class 10 clean room, we will open the canister and start inspecting and taking apart the actual arrays which hold the collector materials. Now, we should point out that you are, I'm sure, more concerned about contaminating your samples than what some people worry about, which is the sample contaminating earth. We're not bringing anything back to Earth's isn't here already in terms of atoms. Because we've been living through the solar wind for an awfully long time now. already in terms of atoms. Because we've been living through the solar wind for an awfully long time now. You, I assume, then, will be spending some time at that lab in Houston,

eagerly taking a look at what you brought back. You have to, even though it's almost cliche now, talk about the actual amount of sample material. I have had this question before. Again, there are various numbers floating around. As scientists, when we talk about analyzing the collected solar wind, we talk in terms of extracting and counting atoms. So we think in terms of atoms. Even if you exclude the hydrogen and helium, which is the majority of what's in the solar wind, we still have a billion, billion atoms to work with, and that's a fairly large sample. Even with everything that we know about the sun, we certainly have learned a lot without

being able to return a sample, as we're about to. We know that there are some mysteries here. Do we really know why the sun is so different from, let's say, a rocky little place like Earth? Well, the big, big order of magnitude difference is the sun has collected all the gaseous materials, hydrogen and helium, whereas the Earth is just not big enough, or more precisely, the temperatures under which the Earth formed were too hot to retain these lighter gases. And so most of the gaseous materials now in the sun

has been lost on the Earth. That's the big, big, big difference. We are looking at the thing at a much more sophisticated level in terms of asking why, as we know in some cases, there are differences in the isotopic composition of something almost between the sun and the Earth, and how did that happen? And that's really where I wanted to go with this, was what do you expect you may learn about Earth and other planets in the solar system?

Okay, in planning for the analysis of the collected solar wind, we identified 18 different what we call measurement objectives. These are things we were going to do. And we used these in designing the collector materials that we were going to use and so forth. Of these 18, the first five or six objectives all involve isotopic measurements. The number one science priority on our list is to measure the oxygen isotopic composition, the relative amounts of oxygen, 16, 17, and 18, which we know or we say is very, very likely to be different in solar matter than it is on Earth. And those, of course, being isotopes of the basic element, oxygen.

Right. We have only a couple of minutes left. We frequently have people on this show who have spent years of their life planning a mission, seeing it launched, waiting patiently while it's in space, getting bits of data back. And then eventually, as just happened with Cassini, you reach a climax like this. You have been waiting for this for a long time. That's true. But in the case of Genesis, getting the material back on Earth is just the beginning.

The real science phase of Genesis starts on September 9th. So how much time will you be spending away from Caltech and at that lab in Houston? At least a week to begin with, and I'll be back and forth in September and during October. Talk a little bit about what your relationship has been with JPL and the engineers there, and for that matter, for the rest of your team, because this is not something anybody does by themselves. Oh, no, no, no. Genesis, of course, is a large project with contributions from JPL, from Lockheed Martin,

from Los Alamos, from the Johnson Space Center. It's been a unique experience. I have the greatest respect for the engineering and navigation people at JPL and at Lockheed Martin in doing this. Our JSC collaboration has been there from the beginning. JSC is a designated repository for all sample return missions, but we brought them in very early because we had to handle our materials very cleanly, and they are very good at that. And so this has all been, it's worked very well. We have all these groups, as we speak, working together, setting up to process and handle the return capsule in Utah. Last question, Don Burnett, but you are both principal investigator and lead scientist.

Is that somewhat unique or at least rare? Not in Discovery missions. In the bigger so-called flagship missions where you have lots of instruments and things, it's hard to wear both hats. I've done this in the case of Genesis, and I think that's probably true for a lot of the other Discovery missions as well. We'll let you go. I know that there are lots of other reporters waiting to get a hold of you.

In fact, you think that you've had calls from the Associated Press. So we at the Planetary Society are certainly flattered that you could take this time. By the way, that Ray Brambury story, I'm going to check it, but I think it was called Golden Apples of the Sun. I would appreciate the reference. So good luck with your own golden apples returning to Earth shortly. Don Burnett is a Caltech professor, planetary scientist, and as we said, principal investigator and lead scientist for the Genesis mission, which for some of you listening to this program, is only hours away from returning samples of the solar wind and, for that matter,

the sun itself to Earth for Don and his colleagues to study. We'll be back right after this return visit from Emily. I'm Emily Lakdawalla, back with Q&A. What time do things happen on spacecraft? When you have to take the travel time of radio signals into account, you have to start talking about spacecraft event time. Spacecraft event time is the UTC time aboard the spacecraft. If you were to send a signal to the Mars rovers, the spacecraft event time of the signal would be the time of the original transmission plus the one-way light time.

One-way light time for the Mars rovers was about five minutes when they first landed, but it's nearly 20 minutes now that the Earth has moved much farther around the Sun. When the rovers return signals to the Earth, you record Earth Receive Time, which is Spacecraft Event Time plus One-Way Light Time, or ERT equals SCET plus OWLT. Confused yet? It's mission navigators and historians who care the most about keeping these numbers straight. Scientists and engineers care about a different kind of time at the rover's landing sites, good old-fashioned local solar time. The rovers prefer to drive around and take pictures while the sun is up,

and to sleep after the sun is set, living like creatures on the Earth, according to the age-old rhythms of the days and the seasons. Got a question about the universe? Send it to us at planetaryradio at planetary.org. And now here's Matt with more Planetary Radio. Time again for What's Up on Planetary Radio with the Director of Projects at the Planetary Society, Dr. Bruce Betts. Welcome, Bruce. How are you?

Oh, hunky-dory swell, Matt. How are you doing? I'm just fine. We are in the palatial living room once again at the Planetary Society because there are big, important meetings going on in the back. Too important to let radio happen back there, so here we are in the living room. We've shut everybody out. Not that Matt has issues. So anyway... What's up, Bruce? Oh, okay. In the pre-dawn sky, that's where things are happening these days.

You can see Venus extremely bright in the east, and you'll see Saturn nuzzling up to it. It's as close as two degrees away, for those of you playing the degree game. You can watch it over the days moving farther away in the sky relative to the position of Venus. So find really bright Venus, and then Saturn will be to its upper left, continuing to get higher up. And if you look further to the upper left, you can actually see Pollux. And to the upper left of that, Castor, its buddy in Gemini. A little star information just to mix things up. Now we've got Mercury coming to make an appearance here in September. It will be far to the lower left of Venus in that pre-dawn sky.

Also in the east, it will be getting higher as you move into mid-September, so a little bit easier to see. It will also look like a bright star, but not nearly as bright as Venus is, but still quite noticeable down low in the horizon. Wonderful. And I especially like that we've addressed a few things that are light years away, like Castor and Pollux, things that are light years away. Castor and Pollux, those fun twin stars.

Yeah, yeah. Sorry, I was so overcome by the profundity of it. You became thoughtful all of a sudden. I know. Don't worry, folks. It doesn't happen often, as the regular listeners know. Let's move on to this week in space history. 1979, that was, I don't know, 25 years ago? Yeah. Yeah. About that.

September 1st, Pioneer 11 became the first spacecraft to fly past Saturn. Yay! Moving on to Random Space Fact! We've been hearing in this show about the first sample return in a really long time from deep space. Apollo 11, which was the first successful lunar sample return, returned 20 kilograms, or about 44 pounds, of samples of lunar rock and dust. You can compare this, although not fairly, to Genesis returning 10 to 20 micrograms. A few grains of sand worth, we were told.

Now, first of all, they're collecting really little stuff in the solar wind, so they don't have much other choice. The other thing to rejoice about is that the technology today, 35 years later, allows people to do things with little, teeny, tiny samples of stuff that are comparable to what required much more at the time of apollo at least many of the analysis not all of them science marches on dun dun dun on to our trivia contest speaker speaking of marching on a couple weeks ago we asked you what space mission included the first ever space docking the actual spacecraft come in contact with each other because there were some that came close but didn't dock.

What docked first? And how'd we do, Matt? Again, we did well. The listeners did well. And we have a winner. Yes, we have a winner. Scott Borgsmiller. Scott Borgsmiller proving

that resistance is futile. What? Well, you know, I'm sure he's never heard that one before. Scott is our winner this week. He hails from Ijemsville, Maryland. Ijemsville, Maryland. Can you believe it? And he had the correct answer, which was Gemini 8.

Gemini 8 piloted by, guess who? David Scott and Neil Armstrong. You just mentioned Apollo 11. Docked with an unmanned Atlas Agena booster. Actually went right up and locked up with that thing. What, proving out a key technique that was going to be necessary to reach the moon. Exactly. It's the first step in proving it out.

They did have some interesting challenges and problems with thrusters on it that got them spinning very, very rapidly, but they were able to correct it after a very scary period. Got crazy for a minute or two there, right? Yeah, yeah. That was even after the spinning stopped. Just kidding. Okay, let's move on to the next trivia question for all of you.

What was the last mission before Genesis to return samples from deep space? In this case, we mean beyond low Earth orbit. The moon would count. What was the last mission to return samples from deep space? To answer, go to planetary.org slash radio. Find out how to enter our contest. Win the wonderful and beautiful Planetary Radio t-shirt. Be the envy of all your friends.

And when do they need to enter by, Matt? They need to get those entries into us for this particular contest by Wednesday, September 8 at noon Pacific time. Bruce, Wednesday, September 8 to be a part of this contest. Fabulous. And if they would, folks, if you're going to enter the contest, make it easy on us and yourself because who knows, you might win. Give us your shirt size right up front so you can easily and quickly get one of those Planetary Radio t-shirts. And be sure to give us your mailing address as well, unless you don't want the shirt. In which case, don't, I guess. Yeah.

Okay. I think we're there. Oh, except for one more little thing we have to take care of. Last week, when we talked about the Perseid meteor shower, and we had a winner who got the answer right, and the question was, what comet was responsible for the debris that the Earth travels through causing the Perseid meteor shower? And we gave people, everyone, gave you the winner, the question. We just skipped one little detail.

Yeah, your little moderator here left out that the correct answer was comet is comet swift tunnel. So that is. So there you go. Now you can feel complete and go on with your lives. Yes, I know. God, everybody's been holding their breath for a week. Are we done? Yes, we are.

Everyone go out there, look up in the night sky, and think about the soothing sounds of flowing water. Thank you. Good night. That's Bruce Betts, the Director of Projects for the Planetary Society, who joins us each week here on What's Up. Join us next time when we'll bring you breaking news of planets circling other stars. I'm Matt Kaplan, hoping all of you have a great week.